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Zorluk: OrtaCommon Ports and Protocols

A network engineer is configuring access control lists (ACLs) on a perimeter firewall to support infrastructure maintenance and monitoring. The configuration must allow network routers to synchronize system clocks with an internal time server and send asynchronous event notifications to a centralized monitoring station. Which of the following port and transport protocol combinations must be permitted through the firewall? (Select TWO.)

  1. UDP port 123Cevap
  2. UDP port 162Cevap
  3. C
    TCP port 123
  4. D
    TCP port 162

Cevap

UDP port 123 and UDP port 162 must be permitted.
Network Time Protocol (NTP) relies on UDP port 123 to synchronize device system clocks with low overhead and minimal delay. Simple Network Management Protocol (SNMP) traps use UDP port 162 to asynchronously push alert notifications from network devices to a central management server.

Adım Adım Çözüm

1
Identify the required network service for time synchronization.
Network Time Protocol (NTP) is identified, which utilizes UDP port 123.
NTP requires fast, connectionless delivery over UDP to calculate clock offsets without TCP handshake latency.
2
Identify the required service for sending asynchronous event notifications.
SNMP Trap delivery is identified, which operates over UDP port 162.
Managed devices push asynchronous trap messages to the SNMP manager on UDP port 162 (whereas standard SNMP queries use UDP port 161).
3
Select the correct protocol options matching these requirements.
UDP port 123 and UDP port 162 are selected.
Both NTP time synchronization and SNMP traps utilize UDP as their transport layer protocol.

Anahtar Kavram

Standard Well-Known Ports for Network Management (NTP and SNMP Traps)
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Konular

Common Ports and Protocols

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